Just ask anyone who voted for Fred Thompson in the 2008 Republican presidential primary. The former U.S. senator from Tennessee, fresh from a starring role on TV's "Law & Order," entered the race with huge fanfare. Then he faded. And then he dropped out following dismal showings in Iowa, New Hampshire and South Carolina.

He left the race a week before Florida's 2008 primary, which meant 1,667 people in Broward and Palm Beach counties who voted for Thompson missed the chance to vote for another Republican candidate. (Admittedly, some of them still could have gone with Thompson after he dropped out, as a show of support for the actor-politician).

And it could happen again, with the Iowa caucuses on Jan. 3, the New Hampshire primary on Jan. 10 and the South Carolina primary on Jan. 21.

It's hard to imagine the Republican field won't shrink after those states' voters deliver verdicts on the candidates. In fact, the number of candidates has already narrowed. On Wednesday, former New Mexico Gov. Gary Johnson ended his long-shot bid for the Republican presidential nomination, but the ballots being sent to Florida voters still have his name on them. Herman Cain, who "suspended" his campaign in early December rather than dropping out, also appears on Florida's primary ballot.

Sid Dinerstein, chairman of the Palm Beach County Republican Party said if he were an absentee voter, he wouldn't hurry to cast his ballot – at least not before Iowa and New Hampshire.

"I would caution them to hold onto their ballots as long as they can," he said. "Everything is so fluid. The movement in polls is so dramatic. They don't have to send them in until after New Hampshire. And that would be my advice."

Absentee ballots aren't due until Election Day, said Cooney and Palm Beach County Supervisor of Elections Susan Bucher.

They need to be returned to the Supervisor of Elections Office in the county where a voter lives by the time the polls close, at 7 p.m. Jan. 31. Postmarked ballots don't count if they're not at the elections office by poll closing time.

So there's no harm in waiting.

Well, almost no harm. Postal rates go up on Jan. 22. Bucher and Cooney said it will cost $1.08 to mail in your absentee ballot before that date. On or after the 22nd, it'll cost $1.10.